I recently ran across some site stats and noticed we do an amazing job at answering 99% of the questions asked on tridion.stackexchange. I think this means we have a very active community and asking a question is worth the effort. From my experience on this site I know that the quality of the questions & answers, and the speed of answering is also pretty amazing.
I think the next step is to ask more questions and give more answers.
Ask more questions, even if you have a simple question, if you answered your own question through your research or if you think no one knows the answer on your questions. I have been surprised quite a few times with the in depth details on ECL, ADF and SmartTarget answers lately while these topics are a bit of a niche in Tridion (for sure it helps that some R&D folks are active on the site).
Just put more of your questions on the site, and it will make a healthier site which will draw more users, and make a busier retreat in Portugal ;) I am sure that we have more than 3.8 questions per day.
Give more answers, even if you don't know the fully detailed scientifically proven tested answer in proper English. Don't think that your answer will have to compete with other answers. The most valuable questions on tridion.stackexchange are those which have multiple answers, answering in various level of detail, with different opinions, different practices. Consider to answer your own question, a great way to share your knowledge. Currently we are doing 1.9 answers per question.
At 480 visits a day have almost accomplished the goal of 500 visits a day. I am sure that with more questions an answers we will also draw more traffic which helps founding a healthy site.